This invention relates to certain new and useful improvements in remote control vehicle security systems, and more particularly, to remote control vehicle security systems including a receiver-control unit located in the vehicle, and one or more remote transmitters, and which systems are electronically programmable by the user without knowledge of the specific transmitter code.
In recent years, primarily due to the increase of theft, vandalism and burglaries, many vehicle owners have installed remote control security systems. The vast majority of these security systems, when triggered, will generate an audible or visible alarm signal to alert of an improper entry or intrusion into the vehicle. Many of these commercially available security systems are remotely operable, that is, they include a receiver capable of being operated from a remotely located transmitter for purposes of arming and disarming the security system. Usually, these receiver-transmitter arrangements are radio frequency operated, although they can be operated with other forms of electromagnetic radiation or sound energy.
Automotive vehicle security systems known in the art usually include an alarm section which may either generate an audible alarm, as for example, from a siren, a horn, or the like and may also often activate a visible alarm by operating any of the vehicle lights. Many of these commercially available vehicle security systems may also disable some portion of the vehicle engine system such as the ignition system, starter, fuel pump, or lock the engine compartment. Thus, in the event of an improper intrusion or attempted theft of the vehicle, the security system will cause initiation of an audible alarm or cause the lights to switch on and off and may also interfere with operation of the vehicle engine system. One example of a remote control vehicle security system is disclosed in U.S. pat. No. 4,383,242.
The use of a transmitter and a receiver which have been precoded is generally standard with commercially available remote control vehicle security systems. In these conventional transmitter-receiver combinations, the code, usually referred to as an encoded signal, is permanently encoded into the receiver, and the transmitters is preprogrammed with a code which cannot be altered or changed by the user. Thus, the receiver is operated on the basis of a security code permanently encoded in that receiver and transmitted from a particular transmitter matched and sold with that receiver. Such conventional security systems present a security exposure in case of a lost or stolen transmitter, as well as many constraints on the manufacturers, customers and dealers of these security systems. For instance, if the user of one of these security systems should lose the transmitter, it is necessary to obtain another transmitter which was not previously coded and have that transmitter properly matched and coded for the particular receiver.
The encoding of the transmitter entails obtaining the particular code required to activate the receiver, opening the transmitter housing and mechanically coding the transmitter. Usually, the coding is accomplished by scratching conductive lines on a printed circuit board, closing or opening switches or the like. Some transmitters are provided with control boards having hole areas capable of being punched to provide a particular encoded signal. Thus, some form of mechanical action is usually required for encoding the transmitter.
Most users of remote control vehicle security systems do not have the expertise to encode the transmitter and, therefore, must seek the assistance of the retailer or manufacturer of the system. The mere fact that the code for authorized actuation of the security system must be known by the selling dealer or manufacturer may inevitably lead to a breach of the security system itself, since the code is usually written to maintain a permanent record of the same. More importantly, should the user wish to change the code because of a lost or stolen transmitter, the receiver will have to be sent back to the manufacturer, leaving the user without the security system while this costly task is being performed.
In addition to the foregoing, if a user desires to have several transmitters operate the receivers of several remote control vehicle security systems, each receiver must be properly programmed with the proper code. Thus, if a person desired to operate several vehicles with the same remote control system, it is necessary to have a receiver in each car preprogrammed by a manufacturer. This necessarily requires custom design efforts which is very time consuming as well as costly.
It is, therefore, one of the primary objects of the present invention to provide a radio frequency operated remote control vehicle security system in which the receiver of the system can be electronically programmed by the user of the system without opening the transmitter, and without coding the transmitter or changing or encoding the receiver or acquiring dealer or manufacturer assistance.
It is another object of the present invention to provide a remote control vehicle security system in which neither the manufacturer, dealer or user of the system is required to know the particular code which is transmitted from the transmitter to the receiver.
It is a further object of the present invention to provide a method for a user of a remote control vehicle security system to encode a receiver from a transmitter without any prerequisite skill or the need to even open the case of either the transmitter or the receiver.
It is an additional object of the present invention to provide a remote control vehicle security system where different types of transmitters may be provided and where each transmitter may operate with different numbers of possible code bits.
It is yet another object of the present invention to provide a remote control vehicle security system where several transmitters, each with a different code, may be added to or deleted from the system at will by the user.
It is another salient object of the present invention to provide a remote control vehicle security system which can be activated by one or more of a multi-billion number of possible codes, thereby providing code security of at least two thousand times the code security of prior art systems and yet which can be manufactured at a relatively low cost.